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Helper III
Helper III

HTTP authentication to Xero

I am trying to use the HTTP action to connect to the Xero api using Client Certficate for their OAuth 1.0 authentication method.

Xero have private and public app options. I am using the Private app option.

I have used OpenSSL to produce the .cer and .pfx files and converted the .pfx file to base 64.

The Private app is registerd with Xero and I have a consumer key and token, even though the token is not needed for private app connections.


What I cant find anywhere is guidance on how to populate the fields in the HTTP action in Flow.

I.e. the headers, query and body.


At the moment I get an error to do with the password. "Could not load the certificate private key. Please check the authentication certificate password is correct and try again."

However I think the problem is bigger than that.


Any guidance would be greatly appreciated.



Accepted Solutions

Cheers Martin. I will leverage our developers to look at building a custom connector like you have outlined below. Thanks again. 

View solution in original post

Community Support
Community Support

Hi @MartinHutchcpa,


It seems that you are trying to use the HTTP action to make requests with Microsoft Flow, please check the following blog for a reference:

By the way, here is a blog on HTTP trigger for your reference:

In addition, there is a request on new connector Xero, please feel free vote the idea at here:


Best regards,


Community Support Team _ Mabel Mao
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Thank you, but this does not address how to setup the authentication using Client Certficate.

@MartinHutchcpa I have also come across the same issue of not being able to authenticate to the Xero API via MS Flow.


None of the three authentication options within MS Flow look compatible with Xero.


This is an example of the private app details generated within Xero:



I can't seem to find a definitive answer on whether oauth 2.0 is backwards compatible or not?



Helper III
Helper III

It turns out the it is not possible.

For reference. 

  • Create a logicApp to generate the authorisation header for each of the GET, POST and PUT calls
    • Use parameters for URi and custom keys etc
  • Export to Flow as a custom connector
  • Pass parameters to Logic App to generate and return Authorization header string
  • Use HTTP call to retrieve json from Oauth 1.0 Xero source

Great thanks Martin,


Did you happen to stumble across instructions on setting up logicapp to generate the authorisation header by chance? Is this the process you are referring to?

I had some guys write the code in c#, deploy it to our Azure logic app space. The code generated the header.

Then I exported to flow to create the custom connector.

The logic app had parameters: -


-consumer key and secret

-pfk password. (I had previously created an ssl cert using OpenSSL)

Happy to provide details of guys I paid to write above code. It only took about an hour.

Cheers Martin. I will leverage our developers to look at building a custom connector like you have outlined below. Thanks again. 

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